1 Field of the Invention
The present invention relates to a diaphragm regulator with a removable diffuser.
2. Description of the Related Art
Many industries, including the oil and gas industry, require regulators for controlling the pressure and flow of fluids. It is customary to install regulators in parallel so that if one fails, the other will take over to maintain flow to the user. One of the more common regulator designs includes a diaphragm located at the end of a vertically aligned piston. In order for a horizontally oriented pipeline to make use of the regulator, the fluid is initially directed downward and then back up past a seat. The fluid must then be directed back to the original horizontal direction. This sudden change in flow direction causes turbulent flow patterns.
Turbulent flow poses several problems. It can cause impingement resulting in damage to the regulator and the surrounding sections of pipeline. Additionally, turbulent flow can cause a great deal of noise. Some of these problems have been addressed previously, in U.S. Pat. No. 3,900,475 to Myers for a low noise valve trim.
The present inventor has addressed the issue of turbulence and noise in a poppet style control valve in U.S. Pat. No. 5,769,388 which includes a flow diffuser with a plurality of vanes. U.S. Pat. No. 5,769,388 is incorporated herein by reference in its entirety. In addition, the present inventor has developed a 90.degree. elbow which includes a plurality of vanes to reduce turbulence and encourage laminar flow in a U.S. patent application that was filed on Jul. 23, 1999, serial number 09/360,424, entitled Flow Diffuser.
The present inventor has also addressed the issue of turbulence reduction in U.S. Pat. No. 5,307,830 which includes a plurality of tubes downstream of a valve. A similar tubular arrangement has been used to redistribute stratified liquids in a pipeline in U.S. Pat. No. 5,454,640. This tubular design has also been used by the present inventor to reduce turbulence in flow regulators and valves in U.S. Pat. No. 5,730,416 and U.S. patent application Ser. No. 09/035,559 filed on Mar. 5, 1998, now U.S. Pat. No. 5,924,673.
The problem of aerodynamic noise in pilot operated pressure reducing regulators has been recognized in the industry for many years and a number of other approaches have been developed to address the problem. For example, Fisher.RTM. has sold the Whisper Trim.RTM. cage in an attempt to reduce operating noise levels in valves and regulators that control gas, vapor or steam. Included in the Information Disclosure Statement ("IDS") filed concurrently herewith, is a copy of a Fisher advertising brochure entitled "High-Performance Control." A photograph of a Whisper Trim cage is shown on page 6 thereof. Also included in the IDS is a copy of Fisher Bulletin 71.2:399A-161 entitled "Type 399A Pilot-Operated Pressure-Reducing Regulator", which includes a photograph of a different Whisper Trim cage on page 4 thereof. Fisher Bulletin 80.1:006 entitled "Whisper Trim I Cage" is also included with the IDS. The Whisper Trim I Cage includes a plurality of slits arranged radially in the cage. Yet another Fisher cage design is shown in Bulletin 80.1:010 entitled "Whisper Trim III Cages" which is also included in the IDS. The Whisper Trim III uses a multi-hole pattern arranged radially in the cage.
In addition to the Whisper Trim line, Fisher also has marketed the Whisper Flo.TM. trim for use in valves that control gas, vapor or steam. The Whisper Flo has a multi-path multistage design as shown in the advertising brochure entitled "Whisper Flo Trim" included in the IDS. This advertising literature claims that aerodynamic noise is reduced by as much as 40 dBA and that this surpasses conventional noise reducing trims by 5 to 10 dBA. Also included in the IDS is Fisher Bulletin 80.3:010 showing the Whisper Flow Trim.
Recently Fisher introduced the Type EZR device to reduce noise in boot and plug regulators. The term boot and plug appears to be a term used by Fisher to describe a regulator that applicant describes as a diaphragm regulator. Also in the IDS is a reprint from the May 1999 Pipe Line & Gas Industry magazine that shows the metal plug used in this product. The EZR device also uses a flow cage with a plurality of radial slits. Additional photos of this cage are shown on pages 1-3 of Fisher Bulletin 71.2:EZR included in the IDS.
For many years, Fisher has offered the CAVITROL.RTM. trim for use with valves that control fluids. Older versions shown in Fisher Bulletin 80.2:020, included in the IDS, use a multi-tube design. The Cavitrol III one-stage trim shown on Fisher Bulletin 80.2:010, included in the IDS, uses a multi-hole design, which appears similar to the Whisper Trim III cage design in Fisher Bulletin 80.1:010.
Other cage designs are used in the industry. For example, the American Meter Company sells RFV.TM. radial flow valves which are pilot-operated diaphragm regulators used for pressure regulation, overpressure relief, flow control or for on/off applications. Also in the IDS is an advertisement from American Meter which shows a picture on page 3 of the trim cages offered in conjunction with the RFV valves.
Some diaphragm regulators have a plate or cage with struts or a grid to support the diaphragm. For example, Mooney Controls uses a throttling plate shown on the front plate of its advertising brochure, a copy of which is included in the IDS.
Patent abstracts of Japan, Publication Number 59140973, Application Number 58013899, a copy of which is included in the IDS, discloses a valve with a comblike cylinder comprising a plurality of square pillar-like members to supposedly reduce noise. These square pillars are counter productive to reduction of turbulence and noise and differ from the streamlined curvilinear vanes of the present invention. U.S. Pat. No. 4,022,423 discloses a control valve with streamlined vanes, but they are designed for rotation under the flow of fluid, to impart rotational movement to a shaft.
These and other types of cages and trims have been used in an attempt to reduce turbulence, impingement and aerodynamic noise in valves and pressure regulators. There is still a need for devices that further reduce turbulence, impingement and noise and produce laminar flow as the fluid exits the regulator.
It is thus an object of this invention to provide a flow diffuser for a diaphragm regulator that produces laminar flow patterns in the fluid upon exiting the valve trim.
It is a further object of this invention to provide a flow diffuser for a diaphragm regulator that reduces impingement and abrasive cutting upon the diaphragm regulator and the surrounding pipeline, thus extending the life of the regulator.
It is a further object of this invention to provide a flow diffuser for a diaphragm regulator that reduces the energy loss in the flow, thus reducing the cost of moving the fluid through the valve.
It is yet a further object of this invention to provide a flow diffuser for a diaphragm regulator that limits the noise caused by the flow through the valve.
Other objects of the invention will become apparent from the specification described herein below.